// 
// ScrollActions.cs
//  
// Author:
//       Mike Krüger <mkrueger@xamarin.com>
// 
// Copyright (c) 2012 Xamarin Inc. (http://xamarin.com)
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

using System;


namespace Mono.TextEditor
{
	static class ScrollActions
	{
		public static void Up (TextEditorData data)
		{
			var newValue = System.Math.Max (data.VAdjustment.Lower, data.VAdjustment.Value - data.VAdjustment.StepIncrement); 
			if (data.Parent != null)
				data.Parent.SmoothScrollTo (newValue);
		}
		
		public static void Down (TextEditorData data)
		{
			var newValue = System.Math.Min (data.VAdjustment.Upper - data.VAdjustment.PageSize, data.VAdjustment.Value + data.VAdjustment.StepIncrement); 
			if (data.Parent != null)
				data.Parent.SmoothScrollTo (newValue);
		}
		
		public static void PageUp (TextEditorData data)
		{
			var newValue = System.Math.Max (data.VAdjustment.Lower, data.VAdjustment.Value - data.VAdjustment.PageSize); 
			if (data.Parent != null)
				data.Parent.SmoothScrollTo (newValue);
		}
		
		public static void PageDown (TextEditorData data)
		{
			var newValue = System.Math.Min (data.VAdjustment.Upper - data.VAdjustment.PageSize, data.VAdjustment.Value + data.VAdjustment.PageSize); 
			if (data.Parent != null)
				data.Parent.SmoothScrollTo (newValue);
		}

		public static void Top (TextEditorData data)
		{
			if (data.Parent != null)
				data.Parent.SmoothScrollTo (data.VAdjustment.Lower);
		}

		public static void Bottom (TextEditorData data)
		{
			var newValue = System.Math.Max (data.VAdjustment.Lower, data.VAdjustment.Upper - data.VAdjustment.PageSize);
			if (data.Parent != null)
				data.Parent.SmoothScrollTo (newValue);
		}
	}
	
}